Regardless of what form symptoms take (SKIN RASH, tingling around the MOUTH, DIARRHEA), a type I hypersensitivity reaction is a systemic response-it affects and involves the body as a whole.
How to Read Your Eyeglass Prescription. The first step to understanding your eyeglass prescription is knowing what OD and OS mean. They are abbreviations for oculus dexter and oculus sinister, which are Latin terms for right eye and left eye.
OD is thus right eye. 1  The cornea is the outer cover of the eye's hole allowing light in. 2  The iris is the muscle that pulls the opening in the eye (the pupil) open (the coloured bit).  The lens is like an internal pair of glasses that focuses the light that comes through the cornea onto the retina.